Updated 03/24/14 – 4:30 p.m.
CHICAGO (CBS) — The operator of the CTA Blue Line train told union officials that she dozed off before the train jumped the tracks and slammed into an escalator early Monday morning at the O’Hare station.READ MORE: Chicago Weather: Wind Chill Advisory In Effect Wednesday Morning
Two sources told CBS 2 that the operator has signed a statement acknowledging she did fall asleep briefly.
The train approached the bumping post at a speed between 15 and 25 miles an hour, the source tells CBS2.
The train should have been slowing from a crawl to a stop.
It appears the “track trips” worked, the source said. These are a series of metal bars that rise up when a sensor determines the approaching train is coming in too fast for conditions.
The mass of the 320,000 pound train appears to have blown right past the first of two of these trips.
Earlier Monday, federal authorities said it’s too soon to tell how fast the train was going when it derailed at O’Hare International Airport early Monday, or why the train failed to slow down, and ended up jumping the tracks, and crashing into the escalator.
A six-person team from the National Transportation Safety Board will be investigating the cause of the derailment, which happened just before 3 a.m.
Officials said an eight-car train failed to stop as it pulled into the O’Hare station, and jumped the tracks, went onto the platform, then went up the escalator, stopping just short of the turnstiles.
Thirty-seven people, including the train operator, were injured in the crash. All had been released from local hospitals by late Monday evening.
NTSB rail investigator Tim DePaepe said it was too early for investigators to know exactly how fast the train was going when it crashed through a bumper at the end of the tracks, and slammed into an escalator. He said investigators would be examining the train, tracks, signals, and other equipment, as well as looking at the possibility of human error in determining what happened.
DePaepe said the NTSB would review surveillance video recorded by cameras inside and outside the train as part of their investigation, to help determine how fast the train was going.
Robert Kelly, president of Amalgamated Transit Union Local 308 — which represents approximately 3,500 CTA workers — said, although it has not yet been ruled out whether the train operator made any mistakes while pulling into the station, Kelly said automated systems should have stopped the train if the operator did not hit the brakes in time. The woman who was operating the train has been at the CTA for about a year.
DePaepe said it was too early to know if there was a malfunction in automated systems designed to stop the train if the operator does not hit the brakes in time. He noted it’s possible there was also a signal error, or that the brakes themselves malfunctioned.
NTSB investigators had not yet interviewed the train operator as of noon Monday, according to DePaepe.